I've been using different cleaners/solvents on a couple of used firearms I've purchased recently. And, over the years I've used all different types of cleaners/solvents. Here's my opinion on what works on what, and other tidbits of useless information. Hoppe's #9: Gently takes out copper; creeps under and causes the edge of lead deposits to peel up over night. Cleans muzzle smog (powder residue) off immediately. Smells like bananas. Penetrant? Kano Kroil: Sold as a penetrating oil, but used by benchrest shooters who swear by it. I've only started to use Kroil, so the jury is still out. Smells like Pinesol. Definately a penetrant. (wonder how it works on rusted bolts?) Hoppe's Elite: It's M-Pro 7. Won't touch copper or clean powder burns off the face of a revolver cylinder, despite what they claim. Seems to clean burnt powder out of the bore as well as M-Pro 7 if you brush, and brush, and brush, ... No odor. Detergent? M-Pro 7: See Hoppe's Elite above. No odor. Detergent? Outers Foaming Bore Cleaner: Gently takes out copper, seems to clean burnt powder out of the bore as well as M-Pro 7 if you brush, and brush, and brush, ... The foam keeps the cleaner in contact with the dirty parts. Smells just like Formula 409. Detergent? Sweets 7.62 Solvent: Agressively and quickly takes out copper just by swabbing with a patch. Removes burnt powder by brushing. STRONG Ammonia odor. Detergent? Blue Wonder Gun Cleaner: Gently takes out copper. Gel keeps the cleaner in place. Removes burnt powder by brushing. Mildly strong ammonia odor. Detergent? JB Bore Compound: Removes copper and burnt power,(very well,) just by swabbing with a patch. Seems to have a very fine polishing grit in a paste. Mild odor. Mildly abbrasive. Remington Bore Cleaner: The liquid equivalent of JB Bore Compound. Remington Bore Brite: (Bore Solvent And Choke Tube Cleaner) Cleans powder residue and plastic wad material. Doesn't touch copper or lead like they claim. Removes burnt powder by brushing. Mild odor. Penetrant?